Estimation of three dimensional, 3D, models from stereo photogrammetric methods is generally known in connection to manual utilization of stereo goggles. There are also solutions utilizing computers and examples of such computerized solutions are inter alias found in our patent applications PCT/EP2007/056780 and PCT/SE2000/000739. Classically the result is based on two images taken from different positions covering the same scene in the world.
From U.S. Pat. No. 5,808,626 and US 2002/0101438 A1 methods using multi overlapping images are known. These methods are based on identifying and selection of key points. Other examples of methods using overlapping images are known from U.S. Pat. No. 6,658,207 B1, US 2004/0105090 A1, US 2002/0163582 A1 and U.S. Pat. No. 5,104,217.
To get accuracy in the automated estimates it is normally required to introduce some kind of smoothing scheme. A drawback with such smoothing is that sharp changes in depth will be smoothed and the overall quality of the 3D model will be very blurred.
It is an object of this invention to obtain a method reducing the need of smoothing resulting in a more stable 3D model requiring none or very little post smoothing.